The effects of 17 alpha-methyltestosterone, methandrostenolone, and nandrolone decanoate on the rat estrous cycle

Prolonged testosterone 17β-cyclopentylpropionate exposition induces behavioral, ovarian, oviductal, uterine and reproductive disturbances in female mice

Anabolic-androgenic steroids (AAS) abuse is often associated with metabolic disorders and infertility. However, the current evidence on AAS-induced reproductive toxicity is mainly based on male studies. Thus, AAS repercussions on female reproductive capacity remain poorly understood, despite scarce evidence that fertility determinants may be more severely impaired in females than males exposed to these drugs. Accordingly, this study used an integrated framework to investigate the impact of different testosterone 17β-cyclopentylpropionate (TC) doses on pain sensitivity, aggressiveness, anxiety, sexual behavior, ovarian, oviductal, uterine and reproductive morphofunctional and molecular outcomes. These parameters were used to explore the reproductive capacity in female mice exposed to this synthetic testosterone ester. The animals were untreated or intraperitoneally treated with 5, 10 and 20 mg/kg TC every 48 h for 12 weeks. Our findings indicated that testosterone was upregulated while the hormones luteinizing, follicle-stimulating, estrogen and progesterone were down-regulated by TC. This AAS also exerted deleterious effects on anxiety, aggressivity, nociception, exploratory and sexual behavior in female mice. Concurrently, TC attenuated ovarian follicle maturation, interrupted the estrous cycle, induced oviductal and uterine hypotrophy. Estrous cyclicity was reestablished 60 days after AAS treatment. However, TC-treated mice still exhibited impaired reproductive capacity, a disturbance potentially related to deficiency in folliculogenesis, sex hormones production, and endometrial receptivity mediate by ER-α, PR, HOXA-10 and LIF down-regulation. Taken together, our findings indicated that in addition to female behavior, reproductive organs microstructure and function are markedly impaired by TC in a dose-dependent manner, whose time-dependent reversibility remains to be clarified.

Nandrolone decanoate causes uterine injury by changing hormone levels and sex steroid receptors in a dose- and time-dependent manner

Different doses of nandrolone decanoate (ND) were used to investigate the expression of uterine sex steroid receptors (AR, ER-α, and ER-β) and the levels of serum sex hormones after treatment and recovery periods in adult rats. ND doses of 1.87, 3.75, 7.5, or 15 mg/kg b.w. or mineral oil (control group) were injected subcutaneously for 15 days, and the experimental groups were divided into three periods of evaluation: (a) ND treatment for 15 days, (b) ND treatment followed by 30-day-recovery and (c) ND treatment followed by 60-day-recovery. Estrous cycle was monitored daily. At the end of each experimental period, rats were euthanized for the collection of serum samples and uterine tissues. All animals showed persistent diestrus and only the highest ND dose was capable of inducing persistent diestrus until 60-day-recovery. Immunoexpression of uterine sex steroid receptors varied in a time-dependent manner. While AR expression was increase after treatment period, ER-α and ER-β expressions decreased after 60- and 30-day-recovery, respectively. ND also increased the serum levels of testosterone, 17β-estradiol, and dihydrotestosterone, especially at the highest doses of 7.5 and 15 mg ND/kg until 30 days of recovery. The levels of progesterone were significantly reduced in all ND-treated animals. No significant difference was observed in the levels of follicle-stimulating hormone, whereas the levels of luteinizing hormone varied according to specific dose and period. We conclude that uterine sex steroid receptors and sex hormones are affected by ND administration and these alterations can be only restored following lower doses and long recovery periods.

High, not low-dose of stanozolol (Anabolic - androgenic steroid) impedes embryo implantation by attenuating endometrial receptivity in the mouse, Mus musculus

The present investigation is aimed at evaluating the efficacy of one of the anabolic -androgenic steroids, stanozolol (ST), on establishment and maintenance of pregnancy in mice. A total of 40 female mice were assigned to three experimental groups. Stanozolol was dosed subcutaneously (low-dose, 0.5 mg/kg bwt; high-dose, 5.0 mg/kg bwt or 1% alcohol-baseline control) for 30 consecutive days. On the 31st day, treatment was withdrawn. The estrous cycle was disrupted in both treatment groups and its resumption was dose dependent. Following estrous resumption, mice were allowed to mate. Results reveal that the low-dose ST-treated mice maintained gestation until term with reduced litter size, while high-dose-treated mice divulged vaginal plug at frequent intervals, indicating conception failure. Because pregnancy failure was noticed in high-dose-treated mice, they were autopsied on GD1.5 and 4.5. Interestingly, neither dose of stanozolol affected early embryonic development or blastocyst hatching. A decrease in the number of corpora lutea in both treated groups suggests it affects either ovulation or recruitment of follicles that occurs in each cycle for maturation. In high-dose-treated mice, decreased serum levels of estradiol, progesterone and increased testosterone along with downregulated endometrial expression of ERα and PR suggest the deficiency of steroid hormones and their respective receptors. Decreased ovarian expression of ERα, hyperexpression of PRLR, AR and abated progesterone secretion led to luteal dysfunction, consequently attenuating endometrial receptivity. Therefore, in high-dose-treated mice, decreased maternal estradiol and progesterone levels and their receptors during implantation hindered signaling to LIF and Hoxa-10, resulting in pragmatic implantation failure.

Histopathological changes in androgenized ovaries are recovered by melatonin treatment

Nandrolone decanoate (ND) is a synthetic steroid, which promotes adverse effects on the ovarian tissue, and melatonin (MLT) exhibits a number of beneficial properties in the reproductive system. This study evaluated the general features of the ovarian tissue and the immunoexpression of sex steroid receptors in ND-treated rats that were submitted to short-term melatonin treatment. Adult rats received mineral oil (control group) and ND at doses of 7.5 mg/kg for 15 days (ND-treated group). The treatment with MLT (10mg/kg for 7 days) was given alone, before or in combination with ND. All ND-treated animals showed persistent dioestrus. In the androgenized groups that received MLT, ovarian morphology and size, and the number/area of corpora lutea were recovered. The number of healthy and atretic follicles was recovered when MLT was administered prior to ND; this was similar to the ovaries of control and MLT groups. There was a decrease in estrogen receptors immunostaining in the follicles of androgenized rats that were treated with MLT, and pretreatment with MLT reduced the expression of androgen receptor in atretic follicles and corpora lutea, when compared with ND-treated group. We conclude that MLT treatment recovered the histopathological aspects of the androgenized ovaries, and MLT pretreatment was the most effective.

Ovarian sex steroid receptors and sex hormones in androgenized rats

This study evaluated for the first time the effects of different doses of the anabolic steroid nandrolone decanoate (ND) on the expression of ovarian steroid receptors (AR, ER-α (ESR1) and ER-β (ESR2)) and related sex hormones after treatment and recovery periods in adult rats. The animals were injected subcutaneously with doses of ND (1.87, 3.75, 7.5 or 15 mg/kg b.w.) or mineral oil (control group) for 15 days, and the experimental groups were divided into three periods of evaluation: (a) ND treatment for 15 days, (b) ND treatment and recovery for a period of 30 days and (c) ND treatment and recovery for a period of 60 days. Estrous cycle was monitored daily. At the end of each period, rats were killed for collection of blood and ovaries. Persistent diestrus occurred in all rats during ND treatment and after 30-day recovery. The highest dose of ND was able to maintain all rats arrested at diestrus until 60-day recovery. The expression of steroid receptors varied in a dose- and period-dependent manner, having a more pronounced response with the dose of 15 mg ND/kg. ND treatment increased serum levels of testosterone, 17β-estradiol and dihydrotestosterone, especially at the highest doses of 7.5 and 15 mg ND/kg. No change was observed in the levels of follicle-stimulating hormone (FSH), whereas levels of the luteinizing hormone (LH) varied according to the dose and period. In conclusion, the ovarian sex steroid receptors and sex hormones were restored only at lower doses of ND and after a longer period of recovery.

Mad men, women and steroid cocktails: a review of the impact of sex and other factors on anabolic androgenic steroids effects on affective behaviors

RATIONALE

For several decades, elite athletes and a growing number of recreational consumers have used anabolic androgenic steroids (AAS) as performance enhancing drugs. Despite mounting evidence that illicit use of these synthetic steroids has detrimental effects on affective states, information available on sex-specific actions of these drugs is lacking.

OBJECTIVES

The focus of this review is to assess information to date on the importance of sex and its interaction with other environmental factors on affective behaviors, with an emphasis on data derived from non-human studies.

METHODS

The PubMed database was searched for relevant studies in both sexes.

RESULTS

Studies examining AAS use in females are limited, reflecting the lower prevalence of use in this sex. Data, however, indicate significant sex-specific differences in AAS effects on anxiety-like and aggressive behaviors, interactions with other drugs of abuse, and the interplay of AAS with other environmental factors such as diet and exercise.

CONCLUSIONS

Current methods for assessing AAS use have limitations that suggest biases of both under- and over-reporting, which may be amplified for females who are poorly represented in self-report studies of human subjects and are rarely used in animal studies. Data from animal literature suggest that there are significant sex-specific differences in the impact of AAS on aggression, anxiety, and concomitant use of other abused substances. These results have relevance for human females who take these drugs as performance-enhancing substances and for transgender XX individuals who may illicitly self-administer AAS as they transition to a male gender identity.

Effects of different doses of nandrolone decanoate on estrous cycle and ovarian tissue of rats after treatment and recovery periods

This study tested the hypothesis that different doses of nandrolone decanoate (ND) will cause changes in the estrous cycle and ovarian tissue of adult rats; and investigated the duration of the recovery period that is sufficient to restore the damage in the animals treated with different doses. Wistar rats were treated with ND at doses of 1.87, 3.75, 7.5 and 15 mg/kg body weight, or received mineral oil (control group) for 15 days, subcutaneously. All animals were divided into three groups according to the treatment periods: (i) ND treatment for 15 days; (ii) ND treatment followed by a 30-day recovery; and (iii) ND treatment followed by a 60-day recovery. Estrous cycle was monitored daily, and at the end of each period, the animals were euthanized for histopathological analysis. During ND treatment and after 30-day recovery, all animals exhibited persistent diestrus. After a 60-day recovery, persistent diestrus was only maintained in the group that had received the highest dose. Ovarian weight was decreased significantly after the 30-day recovery, regardless of ND doses, compared with the control group. There was a reduction (P < 0.05) in the number of corpora lutea and antral and growing follicles, in contrast to an increase (P < 0.05) in atretic follicles in a dose- and time-dependent manner. Remarkable histopathological changes occurred in the ovaries of all ND-treated groups. In conclusion, the different doses of ND caused changes in the estrous cycle and ovarian tissue of rats, and recovery periods (30 and 60 days) were insufficient to completely restore the damage in the animals treated with the highest dose.

Sex-specific effect of the anabolic steroid, 17α-methyltestosterone, on inhibitory avoidance learning in periadolescent rats

The illicit use of anabolic androgenic steroids (AAS) has gained popularity among adolescents in the last decade. However, although it is known that exposure to AAS impairs cognition in adult animal models, the cognitive effects during adolescence remain undetermined. An inhibitory avoidance task (IAT) was used to assess the effect of AAS (17α-methyltestosterone; 17α-meT--7.5 mg/kg) in male and female periadolescent rats. A single injection of 17α-meT immediately before the footshock produced significant impairment of inhibitory avoidance learning in males but not females. Generalized anxiety, locomotion, and risk assessment behaviors (RAB) were not affected. Our results show that exposure to a single pharmacological dose of 17α-meT during periadolescence exerts sex-specific cognitive effects without affecting anxiety. Thus, disruption of the hormonal milieu during this early developmental period might have negative impact on learning and memory.

Estrous cycle variations in GABA(A) receptor phosphorylation enable rapid modulation by anabolic androgenic steroids in the medial preoptic area

Anabolic androgenic steroids (AAS), synthetic testosterone derivatives that are used for ergogenic purposes, alter neurotransmission and behaviors mediated by GABA(A) receptors. Some of these effects may reflect direct and rapid action of these synthetic steroids at the receptor. The ability of other natural allosteric steroid modulators to alter GABA(A) receptor-mediated currents is dependent upon the phosphorylation state of the receptor complex. Here we show that phosphorylation of the GABA(A) receptor complex immunoprecipitated by β(2)/β(3) subunit-specific antibodies from the medial preoptic area (mPOA) of the mouse varies across the estrous cycle; with levels being significantly lower in estrus. Acute exposure to the AAS, 17α-methyltestosterone (17α-MeT), had no effect on the amplitude or kinetics of inhibitory postsynaptic currents in the mPOA of estrous mice when phosphorylation was low, but increased the amplitude of these currents from mice in diestrus, when it was high. Inclusion of the protein kinase C (PKC) inhibitor, calphostin, in the recording pipette eliminated the ability of 17α-MeT to enhance currents from diestrous animals, suggesting that PKC-receptor phosphorylation is critical for the allosteric modulation elicited by AAS during this phase. In addition, a single injection of 17α-MeT was found to impair an mPOA-mediated behavior (nest building) in diestrus, but not in estrus. PKC is known to target specific serine residues in the β(3) subunit of the GABA(A) receptor. Although phosphorylation of these β(3) serine residues showed a similar profile across the cycle, as did phosphoserine in mPOA lysates immunoprecipitated with β2/β3 antibody (lower in estrus than in diestrus or proestrus), the differences were not significant. These data suggest that the phosphorylation state of the receptor complex regulates both the ability of AAS to modulate receptor function in the mPOA and the expression of a simple mPOA-dependent behavior through a PKC-dependent mechanism that involves the β(3) subunit and other sites within the GABA(A) receptor complex.

Effects of administering testosterone undecanoate in rats subjected to physical exercise: effects on the estrous cycle, motor behavior and morphology of the liver and kidney

The aim of the work was evaluate the effects of testosterone undecanoate (TU) treatment combined with moderate physical training on: the estrous cycle, body weight (BW), motor behavior (MB), and the morphohistology of the reproductive system, the liver and kidney in rats. Female Wistar rats (180 g - 250 g) were divided as follows: sedentary + TU (S + TU), trained + TU (T + TU), sedentary + vehicle (S + V), trained + vehicle (T + V). The rats swam 50 min/Day, strapped with a 5% BW load, for 4 weeks. During this training, (BW) was monitored daily as well as the estrous cycle (EC) by vaginal smear. The TU (15 mg/kg s.c) was administered 3 times/week for 4 weeks. At the end of the study, data on MB, BW and morphohistopathological changes in viscera were compiled. The (T + TU) group had on average, a higher (BW) in the fourth week compared to the first week, and (BW) higher than (S + V) and (S + TU) groups. We noted an interruption in the EC and a decrease in weight of ovaries in animals treated with TU. In addition, there was an increase in the relative weight of the heart in groups (T + V) and (T+ TU), and kidneys in group (T + TU). Histopathological analysis showed periportal congestion and isolated foci of hepatic necrosis in rats with TU. Thus, TU combined with training abolished the EC, promoted ovarian atrophy, liver necrosis, cardiac hypertrophy and a decrease in motor activity.

Ovarian histology and follicular score in female rats treated with nandrolone decanoate and submitted to physical effort

The study was conducted to analyze the histology of the ovaries of adults rats treated with steroids, and submitted or not to physical effort. The control group consisted of females submitted to physical effort and sedentary females, both of which received a physiological solution of 0.9% saline. Treated females, sedentary or not, received 6 mg/kg of body weight of nandrolone decanoate. The steroid and physiological solution were administered intraperitoneally, with a single injection per week for 4 consecutive weeks. The applied physical effort was swimming (20 minutes daily, 5 days/week, for the 4 weeks of treatment). Serial sections (5 mum) of ovaries were prepared for histological evaluation and follicular score. The weight of ovaries and hypophysis, the number of antral and atretic follicles, and the area of corpus luteum were all affected by the steroids. In the ovaries of the control groups, well-developed corpus luteum was observed. In the treated groups, the cortical stroma was occupied by ovarian interstitial tissue. The females treated with steroids presented estral acyclicity. The use of nandrolone decanoate, whether associated with physical effort or not, affected the morphological pattern of the ovaries.

Effects of chronic exposure to an anabolic androgenic steroid cocktail on alpha5-receptor-mediated GABAergic transmission and neural signaling in the forebrain of female mice

Anabolic androgenic steroids (AAS) are synthetic derivatives of testosterone that are illicitly self-administered for enhancement of performance and body image, but which also have significant effects on the brain and on behavior. While the stereotypical AAS user is an adult male, AAS abuse in women is rapidly increasing, yet few studies have examined AAS effects in female subjects. We have assessed the effects in female mice of a combination of commonly abused AAS on neuronal activity and neurotransmission mediated by GABA type A (GABA(A)) receptors in the medial preoptic nucleus (MPN); a nexus in the circuits of the hypothalamus and forebrain that are critical for the expression of social behaviors known to be altered in AAS abuse. Our data indicate that chronic exposure to AAS resulted in androgen receptor (AR)-dependent upregulation of alpha(5), beta(3) and delta subunit mRNAs. Acute application of the alpha(5) subunit-selective inverse agonist, L-655,708 (L6), indicated that a significant fraction of the synaptic current is carried by alpha(5)-containing receptors and that AAS treatment may enhance expression of alpha(5)-containing receptors contributing to synaptic, but not tonic, currents in the MPN. AAS treatment also resulted in a significant decrease in action potential frequency in MPN neurons that was also correlated with an increased sensitivity to L-655,708. Our data demonstrate that chronic exposure to multiple AAS elicits significant changes in GABAergic transmission and neuronal activity that are likely to reflect changes in the expression of alpha(5)-containing synaptic receptors within the MPN.

Exposure to an anabolic steroid changes female mice's sexual responses according to sex partner

INTRODUCTION

Anabolic androgenic steroids (AAS) affect human female sexual behaviors. Animal models have been useful in uncovering the neural mechanisms governing changes in female sexual response upon AAS exposure.

AIM

We quantify the sexual response of AAS-exposed gonadally intact female mice when paired with gonadally intact female or male pairs.

METHODS

C57Bl/6 female mice were systemically exposed to the AAS 17alpha-methyltestosterone (7.5 mg/kg) for 17 days via a subcutaneous osmotic implant. On days 15-17, these females were allowed to mate with males or proestrus female partners in familiar and unfamiliar testing arenas for 10 minutes.

MAIN OUTCOME MEASURES

The following behavioral responses were registered: parameters related to mounting behavior such as the frequency of mounts, attempts to mount, and the latency to the first mount, anogenital investigation, fights and escapes, rejections, pelvic thrusts, and lordotic responses.

RESULTS

We found that males displayed a significant decrease in the frequency of mounts to AAS-exposed females, when compared with mating encounters with control females. We found no difference in the lordosis strength when control females were mounted by either a male or AAS-exposed females. However, females under androgen exposure attempted to mount control females, but not males, and their behavior was accompanied by significant increases in the number of fights, escapes, and rejections to the male. There were no differences between AAS-exposed females and males when the frequency of mounts and pelvic thrusts toward control females were compared. The lordotic quotient of control females was similar for either partner.

CONCLUSIONS

Aside from showing a male-like pattern, AAS-exposed females displayed a higher frequency of anogenital investigations toward control females than males, and their latency to the first mount was as fast as that of males. Taken together, we conclude that the sex partner greatly influences the sexual response of AAS-exposed female mice.

Administration of the anabolic androgenic steroid nandrolone decanoate to female rats causes alterations in the morphology of their uterus and a reduction in reproductive capacity

OBJECTIVE

The aim of the present investigation was to characterize the effects of supraphysiological doses of the anabolic androgenic steroid nandrolone decanoate (ND) on the fertility of female rats, as well as on the morphology of their uterus.

STUDY DESIGN

Female Wistar rats (n=15) received a subcutaneous injection of ND (15 mg/kg) once daily during a 2-week period, while the control animals (n=10) were administered vehicle alone (arachidis oleum) in the same manner. Estrus behavior was evaluated 4 weeks after termination of this treatment and in cases where signs of receptivity were present, the female rat was given the opportunity to copulate with a male. After breeding, the female animals were sacrificed and their uteri examined histomorphologically.

RESULTS

All ND-treated animals exhibited abnormal vaginal smears, whereas all of the control smears were normal. Most (73%) of the treated females demonstrated normal estrus behavior (i.e., willingness) on the day of mating, but none got pregnant; whereas all of the control rats became pregnant. The female rats receiving the ND showed an enhanced rate of weight gain and the myometrium thickness of their uteri was significantly increased, while the endometrium was significantly thinner. Furthermore, ND caused a significant proportion of the treated animals to display tortuous and irregularly branching endometrial glands, as well as a lack of the physiologically normal infiltration of eosinophilic leukocytes into the endometrium (endometrial eosinophilic homing), a finding that has not been reported previously.

CONCLUSION

The present findings indicate that high doses of ND cause morphological and physiological alterations in the uterus of female rats that are associated with a suppression of their reproductive capacity.

Histological assessment of ovaries and uterus of rats subjected to nandrolone decanoate treatment

This study aimed to analyze the effects of nandrolone decanoate on the ovaries and uterus of adult females rats. This drug was administered intraperitoneally, at one, two and three doses of 3 mg nandrolone decanoate/kg of body weight, respectively, in the first, second and third week of treatment. The females of the control group received a physiological solution. The rats treated with nandrolone decanoate showed estral acyclicity and there was destruction of follicular units and an absence of corpus luteum in the ovaries. In the uterus, the drug promoted morphological alterations, characterized by vacuolated epithelium and endometrial stroma fibrosis. Ovary, uterus and pituitary weights were not affected by the steroid treatment. Nandrolone decanoate affects the sexual cycle and promotes histological alterations in the ovaries and uterus of adult female rats.

Modulation of affect after chronic exposure to the anabolic steroid 17alpha-methyltestosterone in adult mice

A battery of behavioral tasks in C57BL/6J mice was used to assess changes in affective components of behavior after systemic exposure to the anabolic-androgenic steroid (AAS) 17alpha-methyltestosterone (7.5 mg/kg). Gonadal weight in both sexes was reduced after 16 days of AAS exposure. Changes in discrete components of social behaviors were observed. No changes were recorded in the elevated plus-maze, the light-dark transition, and defensive behavior tests on exposure to 17alpha-methyltestosterone. When compared with controls, AAS-exposed females received a greater number of shocks, and AAS-exposed males displayed a shorter recovery time to consume water after a negative reinforcer in the modified Vogel conflict test. Results show that systemic exposure to a single AAS modified social behaviors, whereas minimal effects on anxiety-related behaviors were observed according to sex.

Intracerebroventricular Self-Administration of Commonly Abused Anabolic-Androgenic Steroids in Male Hamsters (Mesocricetus auratus): Nandrolone, Drostanolone, Oxymetholone, and Stanozolol

Previous studies by the authors have shown voluntary intracerebroventricular (icv) testosterone self-administration in hamsters (Mesocricetus auratus). Here, the authors compared icv self-administration of 4 anabolic steroids (drostanolone, nandrolone, oxymetholone, and stanozolol) at 0.1, 1.0, and 2.0 microg/microl, each for 8 days. Males (n=8/group) showed the highest levels of operant behavior for injectable steroids (drostanolone, nandrolone) compared with orally active androgens (oxymetholone, stanozolol). For nandrolone, responses on the active and inactive nose-pokes averaged 22.3 +/- 4.6/4 hr and 10.7 +/- 2.0/4 hr, respectively. Responding for drostanolone was similar. Males self-administering oxymetholone or stanozolol did not prefer the active nose-poke. These data demonstrate that injectable androgens are more reinforcing than oral steroids.

Testosterone self-administration in female hamsters

Abuse of anabolic-androgenic steroids (AAS) is a growing public health concern. In addition to their anabolic effects, steroids are also reinforcing as demonstrated by testosterone self-administration in male hamsters. However, steroid use in women lags behind that in men. Are androgens also rewarding in females? We determined if female hamsters voluntarily consume testosterone by intracerebroventricular (i.c.v.) self-administration in an operant chamber. Twelve ovary-intact female hamsters self-administering testosterone (1.0 microg/microl) i.c.v. for 19.1 +/- 2.3 days developed a significant preference (P < 0.05) for the active nose-poke (31.5 +/- 6.1 nose-pokes/4 h) over the inactive nose-poke (12.5 +/- 1.1 nose-pokes/4 h). Operant behavior in females was similar to that reported previously for male hamsters. Estrous cycles became irregular 9.6 +/- 2.3 days after the start of self-administration. Regular cycles resumed 13.7 +/- 2.6 days after testosterone was discontinued. To determine the effect of ovarian steroids on androgen self-administration, females were ovariectomized (OVX) and allowed to self-administer testosterone for 10.8 +/- 0.5 days. Afterwards, estrogen was replaced, and self-administration continued for an additional 9.7 +/- 0.6 days. OVX females maintained their preference for the active (23.9 +/- 7.0 nose-pokes/4 h) over the inactive nose-poke (12.6 +/- 3.4 nose-pokes/4 h, P < 0.05), and estrogen had no effect on responding for androgen (active: 25.8 +/- 6.5 nose-pokes; inactive: 8.2 +/- 2.0 nose-pokes/4 h, P < 0.05). Estrous female hamsters did not show a significant preference for stimulus males or females when mating was blocked, and testosterone self-administration did not alter partner preference. However, activity in the preference chamber predicted subsequent androgen intake (R(2) = 0.66, P < 0.05). These findings are consistent with the idea that anabolic steroids have inhibitory effects on female reproduction. Moreover, they suggest that sex differences in androgen reward do not underlie sex differences in AAS abuse in humans.

Reinforcing aspects of androgens

Are androgens reinforcing? Androgenic-anabolic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, often with negative long-term health consequences. As a result, in 1991, testosterone was declared a controlled substance. Recently, Brower [K.J. Brower, Anabolic steroid abuse and dependence. Curr. Psychiatry Rep. 4 (2002) 377-387.] proposed a two-stage model of AAS dependence. Users initiate steroid use for their anabolic effects on muscle growth. With continued exposure, dependence on the psychoactive effects of AAS develops. However, it is difficult in humans to separate direct psychoactive effects of AAS from the user's psychological dependence on the anabolic effects of AAS. Thus, studies in laboratory animals are useful to explore androgen reinforcement. Testosterone induces a conditioned place preference in rats and mice, and is voluntarily consumed through oral, intravenous, and intracerebroventricular self-administration in hamsters. Active, gonad-intact male and female hamsters will deliver 1 microg/microl testosterone into the lateral ventricles. Indeed, some individuals self-administer testosterone intracerebroventricularly to the point of death. Male rats develop a conditioned place preference to testosterone injections into the nucleus accumbens, an effect blocked by dopamine receptor antagonists. These data suggest that androgen reinforcement is mediated by the brain. Moreover, testosterone appears to act through the mesolimbic dopamine system, a common substrate for drugs of abuse. Nonetheless, androgen reinforcement is not comparable to that of cocaine or heroin. Instead, testosterone resembles other mild reinforcers, such as caffeine, nicotine, or benzodiazepines. The potential for androgen addiction remains to be determined.

Effects of androstenedione on in utero development in rats

This study was conducted to characterize the effect of androstenedione on estrous cyclicity, mating behavior and fetal development. Thirty-day old rats received corn oil alone or androstenedione (in corn oil) at one of four concentrations (0, 1.0, 5.0, 10.0 or 30.0 mg/kg body weight) by gavage for two weeks prior to mating, during the mating period and throughout gestation. Dose related increases in serum androstenedione, estradiol and estrone were observed in all androstenedione treated animals at gestation day 20. A statistically significant increase in serum testosterone concentration was observed in the 30 mg/kg dose group. Feed and fluid consumption were not affected by androstenedione treatment during the pre-mating or gestational periods, however a statistically significant decrease in the number of females with regular estrous cycles was observed in the 10.0 and 30.0 mg/kg dose groups. Exposure to androstenedione did not affect mean body weight gain during pre-mating or gestation. Slight not statistically significant reductions in the number of implants, number of viable fetuses and number of viable male fetuses were observed in the 30.0 mg/kg androstenedione group. Reductions were not observed in the number of corpora lutea. Fetal growth in terms of fetal weight, crown-rump length, anogenital distance and the number of external abnormalities was not affected by androstenedione exposure. At the doses given, androstenedione had no specific effect on the development of individual bones, including sternebrae. Dose related effects of androstenedione were not observed on the development of soft tissues. A statistically significant increase in moderately enlarged ureter at the kidney was observed in both the 1.0 and 5.0 mg/kg dose groups. Organ weights (expressed per gram of body weight or per gram of brain weight) were not affected by androstenedione treatment.

Behavioral and physiological responses to anabolic-androgenic steroids

Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone originally designed for therapeutic uses to provide enhanced anabolic potency with negligible androgenic effects. Although AAS continue to be used clinically today, the medical benefits of low therapeutic doses of AAS stand in sharp contrast to the potential health risks associated with the excessive doses self-administered not only by elite athletes and body builders, but by a growing number of recreational users, including adolescent boys and girls. The deleterious effects of AAS on peripheral organs and the incidence of altered behaviors in AAS abusers have been well documented in a number of excellent current reviews for clinical populations. However, a comparable synthesis of nonclinical studies has not been made. Our purpose in this review is to summarize the literature for animal models of the effects of supraphysiological doses of AAS (e.g. those that mimic human abuse regimes) on behaviors and on the neural circuitry for these behaviors. In particular, we have focused on studies in rodents that have examined how AAS alter aggression, sexual behaviors, anxiety, reward, learning, and locomotion and how AAS alter the expression and function of neurotransmitter systems and other signaling molecules that underlie these behaviors.

Chronic administration of anabolic steroids disrupts pubertal onset and estrous cyclicity in rats

Use of anabolic-androgenic steroids (AASs) is becoming increasingly popular among adolescent girls, yet the effects of AASs on female physiology and development are not well understood. The present study compared the effects of chronic exposure to three individual AASs, stanozolol (0.05-5 mg/kg), 17alpha-methyltestosterone (0.5-5 mg/kg), and methandrostenolone (0.5-5 mg/kg) on the onset of puberty and estrous cyclicity in the rat. Female rats received daily injections of AASs for 30 days (Postnatal Day [PN] 21-51). Rats receiving the highest dose of each of the AASs (5 mg/kg) displayed vaginal opening at a younger age than rats receiving the oil vehicle. The day of first vaginal estrus was delayed in rats receiving stanozolol (5 mg/kg) or 17alpha-methyltestosterone (0.5-5 mg/kg) but not in rats receiving methandrostenolone. At the highest dose (5 mg/kg), each of the AASs reduced the incidence of regular estrous cyclicity during the treatment period. Concurrent administration (on PN21-51) of the androgen receptor antagonist, flutamide (10 mg/kg, twice daily), reversed the effects of 17alpha-methyltestosterone (5 mg/kg) on vaginal opening. Flutamide administration also eliminated the effects of stanozolol (5 mg/kg) and 17alpha-methyltestosterone (5 mg/kg) on the day of first vaginal estrus. In contrast, rats receiving flutamide and methandrostenolone (5 mg/kg) exhibited first vaginal estrus earlier than controls. The present results indicate that chronic exposure to AASs during development has deleterious effects on the female neuroendocrine axis and that these effects appear be mediated via multiple mechanisms.

Effects of 17 alpha-methyltestosterone on uterine morphology and heat shock protein expression are mediated through estrogen and androgen receptors

Testosterone and the synthetic androgen, 17 alpha-methyltestosterone (MT), have been shown to increase uterine weights and alter uterine morphology. However, whereas the mechanism of action of testosterone in the uterus has been studied, it is not known if the actions of MT are mediated through androgen (AR) or estrogen (ER) receptors. In the present study, we have shown that MT, at 0.5 or 10 mg/kg per day, increases uterine weight and alters uterine morphology in a dose-dependent manner. Co-administration of the anti-androgen, flutamide, or the anti-estrogen, ICI 182,780, with MT revealed that the effects of the low dose of MT are mediated through the ER, whereas those of the high dose are mediated through both the ER and AR. In addition, we have studied the effects of MT on uterine heat shock proteins (hsps), a group of estrogen-regulated proteins whose levels increase in response to growth signals and protein damage. MT increased levels of hsp90 alpha, hsp72, and grp94. All effects on uterine hsp levels were antagonized by the anti-estrogen and not the anti-androgen. Collectively, the results of the present study indicate that the effects of MT in the uterus are mediated through the AR and ER.

Anabolic androgenic steroids induce age-, sex-, and dose-dependent changes in GABA(A) receptor subunit mRNAs in the mouse forebrain

Chronic exposure to anabolic androgenic steroids (AAS) has deleterious effects on reproductive health in both human and animal subjects. Neurotransmission mediated by the gamma-aminobutyric acid type A (GABA(A)) receptor in the medial amygdala (MeA), the medial preoptic area (mPOA), and the ventromedial nucleus (VMN) of the hypothalamus plays a critical role in mediating sexual behaviors. Here we used semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) to examine levels of alpha(1), alpha(2), alpha(5), gamma(1), gamma(2), and epsilon subunit mRNAs in these three regions of the brain. Our results demonstrate that chronic exposure to either a high or a moderate dose of the AAS, 17alpha-methyltestosterone (17alpha-MeT), significantly decreased the levels of specific alpha and gamma subunit mRNAs in a manner that depended on the dose of AAS and age and sex of the animals. Specifically, the moderate dose of AAS elicited significant changes only in pubertal females and the majority of changes observed in pubertal animals with the high dose also occurred in females. In contrast, the moderate dose of AAS induced no significant changes in adult mice of either sex, while the high dose had effects in both males and females. In addition to determining the effects of chronic AAS treatment, a developmental analysis of drug-naïve animals demonstrated that GABA(A) receptor subunit mRNA levels in these regions of the forebrain undergo significant changes as animals proceed through puberty. These data demonstrate that the effects of AAS exposure on GABA(A) receptor expression are superimposed upon dynamic developmental changes that accompany the transition from puberty to adulthood.

17alpha-methyl testosterone is a competitive inhibitor of aromatase activity in Jar choriocarcinoma cells and macrophage-like THP-1 cells in culture

17alpha-methyl testosterone is a synthetic androgen with affinity for the androgen receptor. 17alpha-methyl testosterone is used widely as a component of hormone replacement therapy. Previous reports have indicated that contrary to testosterone, 17alpha-methyl testosterone is not aromatized. However, 17alpha-methyl testosterone still could affect local estrogen formation by regulating aromatase expression or by inhibiting aromatase action. Both possibilities have important clinical implications. To evaluate the effect of 17alpha-methyl testosterone on the expression and activity of aromatase, we tested the choriocarcinoma Jar cell line, a cell line that express high levels of P450 aromatase, and the macrophage-like THP-1 cells, which express aromatase only after undergoing differentiation. We found that in both cell lines, 17alpha-methyl testosterone inhibits aromatase activity in a dose-related manner. The curve of inhibition parallels that of letrozole and gives complete inhibition at 10(-4) M 17alpha-methyl testosterone, determined by the tritium release assay. 17alpha-methyl testosterone does not have detectable effects on aromatase RNA and protein expression by Jar cells. Undifferentiated THP-1 cells had no aromatase activity and showed no effect of 17alpha-methyl testosterone, but differentiated THP-1 (macrophage-like) cells had a similar inhibition of aromatase activity by 17alpha-methyl testosterone to that seen in Jar cells. The Lineweaver-Burke plot shows 17alpha-methyl testosterone to be a competitive aromatase inhibitor. Our results show for the first time that 17alpha-methyl testosterone acts as an aromatase inhibitor. These findings are relevant for understanding the effects of 17alpha-methyl testosterone as a component of hormone replacement therapy. 17alpha-methyl testosterone may, as a functional androgen and orally active steroidal inhibitor of endogenous estrogen production, also offer special possibilities for the prevention/treatment of hormone-sensitive cancers.

Effects of acute stanozolol treatment on puberty in female rats

The effects of anabolic-androgenic steroid (AAS) abuse on the onset of puberty in female adolescents are largely unknown. This study assessed the acute effects of one AAS, stanozolol, on pubertal onset in the female rat. A single injection of stanozolol (5 mg/kg) on Postnatal Day (PN) 21 advanced vaginal opening but did not alter the onset of vaginal estrus. Higher doses of stanozolol treatment (10 and 25 mg/kg) also advanced vaginal opening but had no effect on vaginal estrus. The advancement of vaginal opening by stanozolol (5 mg/kg) was prevented by the concomitant administration of the pure antiestrogen ICI 182,780 (1 mg/kg) on PN20-22. Administration of the androgen receptor antagonist flutamide (10 mg/kg twice daily) on PN20-22 had no effect on the advancement of vaginal opening by stanozolol. Stanozolol treatment also advanced vaginal opening in ovariectomized rats. Perivaginal injections of a low dose of stanozolol (0.05 mg) on PN21 and PN23 also advanced vaginal opening. These results suggest that stanozolol is acting directly at estrogen receptors in the vaginal epithelium to advance vaginal opening and that prepubertal stanozolol treatment does not induce true precocious puberty.

Anabolic steroids induce region- and subunit-specific rapid modulation of GABA(A) receptor-mediated currents in the rat forebrain

Anabolic-androgenic steroids (AAS) have become significant drugs of abuse in recent years with the highest increase reported in adolescent girls. In spite of the increased use of AAS, the CNS effects of these steroids are poorly understood. We report that in prepubertal female rats, three commonly abused AAS, 17alpha-methyltestosterone, stanozolol, and nandrolone, induced rapid and reversible modulation of GABAergic currents in neurons of two brain regions known to be critical for the expression of reproductive behaviors: the ventromedial nucleus of the hypothalamus (VMN) and the medial preoptic area (mPOA). All three AAS significantly enhanced peak synaptic current amplitudes and prolonged synaptic current decays in neurons of the VMN. Conversely all three AAS significantly diminished peak current amplitudes of synaptic currents from neurons of the mPOA. The endogenous neuroactive steroids, 3alpha-hydroxy-5alpha-pregnan-20-one and 5alpha-androstane-3alpha,17beta-diol, potentiated currents in the VMN as did the AAS. In contrast to the negative modulation induced by AAS in the mPOA, the endogenous steroids potentiated responses in this region. To determine the concentration response relationships, modulation by the AAS, 17alpha-methyltestosterone (17alpha-meT), was assessed for currents evoked by ultrafast perfusion of brief pulses of GABA to acutely isolated neurons. Half-maximal effects on currents elicited by 1 mM GABA were elicited by submicromolar concentrations of AAS for neurons from both brain regions. In addition, the efficacy of 10(-5) to 10(-2) M GABA was significantly increased by 1 microM 17alpha-meT. Previous studies have demonstrated a striking dichotomy in receptor composition between the VMN and the mPOA with regard to gamma subunit expression. To determine if the preferential expression of gamma(2) subunit-containing receptors in the VMN and of gamma(1) subunit-containing receptors in the mPOA could account for the region-specific effects of AAS in the two regions, responses elicited by ultrafast perfusion of GABA to human embryonic kidney 293 cells transfected with alpha(2), beta(3), and gamma(2) or alpha(2), beta(3), and gamma(1) subunit cDNAs were analyzed. As with native VMN neurons, positive modulation of GABA responses was elicited for alpha(2)beta(3)gamma(2) recombinant receptors, while negative modulation was induced at alpha(2)beta(3)gamma(1) receptors as in the mPOA. Our data demonstrate that AAS in doses believed to occur in steroid abusers can induce significant modulation of GABAergic transmission in brain regions essential for neuroendocrine function. In addition, the effects of these steroids can vary significantly between brain regions in a manner that appears to depend on the subunit composition of GABA(A) receptors expressed.

Stanozolol, oxymetholone, and testosterone cypionate effects on the rat estrous cycle

Anabolic-androgenic steroid (AAS) effects on the estrous cycle of adult Long-Evans rats were examined in four different experiments. Sexual receptivity, vaginal cytology, and body weight were monitored throughout two-week baseline, AAS treatment, and recovery periods. In Experiments 1-3, rats were administered stanozolol, oxymetholone, or testosterone cypionate within dose ranges selected to mimic the human abuse levels of each compound. In these studies, the highest doses of stanozolol (5 mg/kg), oxymetholone (12 mg/kg), or testosterone cypionate (7.5 mg/kg) disrupted the cyclical display of sexual receptivity and vaginal estrus. To compare effects on estrous cyclicity across AAS compounds, rats in Experiment 4 received a single dose (7.5 mg/kg) of each compound for 2 weeks. At the 7.5 mg/kg dose, all AAS compounds interfered with the cyclical display of vaginal estrus, although effects on sexual receptivity were not uniform. No striking AAS effects on body weight were seen in any experiment. The short-term administration of AAS compounds at high doses disrupts female neuroendocrine function in rats.

Anabolic-androgenic steroid effects on sexual receptivity in ovariectomized rats

Anabolic-androgenic steroid (AAS) compounds are synthetic androgens taken by athletes to increase physical strength and endurance. Recent studies in our laboratory have demonstrated that AAS administration disrupts the estrous cycle of Long-Evans rats. The present experiments examined the effects of six commonly abused AAS compounds on sexual receptivity in ovariectomized rats. Adult female Long-Evans rats received estradiol benzoate (EB; 2.0 micrograms/day s.c.) for 6 consecutive days followed by 15 days of EB concurrent with daily s.c. injections of 7.5 mg/kg of one of the following AAS compounds: 17 alpha-methyltestosterone, methandrostenolone, nandrolone decanoate, stanozolol, oxymetholone, testosterone cypionate, or the oil vehicle. On Day 15, all female rats received progesterone (1.0 mg/rat) 4 h before testing. Tests for sexual receptivity were conducted on Days 3, 6, 14, and 15 of AAS treatment. Although the time course of AAS effects on sexual receptivity varied, some overall effects were clear. For example, 17 alpha-methyltestosterone, methandrostenolone, nandrolone decanoate, and stanozolol interfered with the display of sexual receptivity on Day 14, whereas oxymetholone and testosterone cypionate had no effect. Rats in all groups displayed high levels of sexual receptivity after receiving progesterone on Day 15. Our results show that AAS compounds vary in their degree of inhibition of female sexual behavior in ovariectomized rats.